Well, your single photo gives almost zero indication of what you've got there (to someone who doesn't know what those parts are), or how you built it, so obviously more detail is needed if you want to help people do the same thing.
If you don't want to help anyone else, then you're right, no extra detail is really needed.
What may be obvious to you has me perplexed and I would appreciate some more details on how you did this.
I think all the details have already been explained myself; is there something in particular that you don't understand?
The peristaltic pump has two leads that you connect to the AC to DC adapter (solder the wires together). After that, you just hook up some tubing and feed one end into (say) a fertilizer solution and the other into your aquarium. When the pump is plugged in, it will pump up to 20 mL per minute. Thus, if you put it on a timer for 1 minute, it will pump 20 mL.
Optix just went one step further and put the whole thing into a nice enclosure for presentation. The potentiometer was also put in to control speed, but that's just optional.